complementary color

one of a pair of primary or secondary colors opposed to the other member of the pair on a schematic chart or scale (color wheel) as green opposed to red, orange opposed to blue, or violet opposed to yellow.

complementary colorA secondary color that, when combined with the primary color whose wavelength it does not contain, produces white light. Thus yellow, which is produced by mixing the primary colors red and green, is the complementary color of blue. See Note at color.